5. Okay...

If you fully admit you're both confused and not familiar with US law, you might want to refrain from deciding what is "very clear" from the text, particularly when what you describe is not clear at all.

For one thing, "well regulated" in this context refers to said militias being regular and orderly, i.e. well trained and effective. It has nothing to do with "regulation" of the kind you're thinking about. Also, there's no place which says that that is the sole purpose of bearing arms; a claim which goes against both the unanimous view of the Supreme Court and 200+ years of jurisprudence on the subject.

Thirdly, you probably hear about the US' very well organized militias all the time. They're just not referred to by that title. They are, instead, referred to almost exclusively by their official legal name: the National Guard.